The present invention refers generally to a torsional oscillation damper, especially a friction disk damper, and more particularly to a torsional oscillation damper generally located between the engine and the transmission or other output unit of a motor vehicle to absorb torsional vibrations as generated e.g. by engine firing pulsations.
Conventional torsional oscillation dampers, especially those of the friction disk damper type, are widely used and typically so designed as to have incorporated between the primary part and the secondary part an intermediate disk which is acted upon by tangential compression springs, on the one hand, for resiliently connecting the primary part and the intermediate disk, and pre-damping springs, on the other hand, for resiliently connecting the intermediate disk with the secondary part. When the engine runs idle, no significant torque acts between the primary part and the secondary part so that the intermediate disk is fixedly connected to the primary part, while small vibrations are absorbed by the pre-damping springs between the intermediate disk and the secondary part. In order to avoid resonance, damping mechanisms are provided between the primary part and the intermediate disk and between the primary part and the secondary part.
In idle operation, the tangential compression springs and the intermediate disk form a fixed interconnected unit so that the secondary part has only a small mass and thus is relatively sensitive to vibrations.